As it stands today, the Pentium M is inferior to a Pentium 4 in many cases. It is true that the Pentium M architecture is much more efficient than the Pentium 4, requiring much lower clock speeds to reach high performance levels. But the Pentium M gives up a lot in the area of clock speed - even the fastest Pentium M currently available, the 770 model running at 2.13 GHz, is unable to stand up to a fast 3.2 GHz Pentium 4.

Furthermore, almost all current Pentium 4 models come with Hyper Threading, which is a boon to multitasking scenarios common in everyday work. To the operating system, an HT enabled Pentium 4 appears as two individual CPUs. fact, Hyper Threading technology ensures that the processor's architecture is kept operating at full capacity. The most tangible side effect is that there are practically no more stalls when two programs compete for CPU time.

The Pentium M lacks this feature, for two main reasons. First, the Pentium M is a direct descendant of the Pentium III processor, which predates HT. For another, HT seems to increase a design's power requirements, a trait that is undesirable in a notebook processor.

However, the Pentium M really comes into its own when energy efficiency and low noise are required. None of the current Pentium M processors draws more than 27 watts; even the dual-core Pentium M derivative codenamed Yonah is expected to fit into this thermal envelope. The low overall power draw enables the system's power consumption to remain low, regardless of whether the processor is sitting idle or running at full speed. The Pentium 4, by comparison, requires at least twice as much even under ideal conditions. Under full load, a thermal dissipation loss of about 100 watts can be considered normal - just for the processor, that is.

The Pentium M architecture has no trouble reaching clock speeds of about 2.5 GHz. At this frequency, "the little chip that could" even outperforms Intel's P4 Extreme Edition and AMD's flagship Athlon 64 FX in 3D games. In other applications, the Pentium M also makes a surprisingly strong showing, despite its lack of the SSE3 instruction set and HT. Increasing the chip's core voltage could probably push it even closer to the 3 GHz mark without incurring the kind of thermal dissipation that has caused the Pentium 4 to fall from grace in the eyes of many readers and hardware testers alike.